Nut-lock.



I No. 672,768.- Patented Apr. 23, I90l.

T. W. HINE.

NUT LOOK.

(Application filed Dec. 15, 1900.) (No Model.)

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"a side elevation of my invention.

UNITED STATES ATENT OFFICE.

THOMAS W. HINE, OF SCOTCHGROVE, IOWA.

NUT-LOCK.

SPECIFICATION forming part of Letters Patent N 0. 672,768, dated April23, 1901.

Application filed December 15. 1900. Serial No. 40,021. (No model.)

To all whom it may concern.-

Be it known thatI,THOMAs W. HINE, a citizen of the United States,residing at Scotchgrove,in the county of Jones and State of Iowa, haveinvented certain new and useful Improvements in Nut-Locks; and I dodeclare the following to be a full,clear, and exact description oftheinvention,such as will enable others skilled in the art to which itappertains to make and use the same, reference being had to theaccompanying drawings, and to the figures of reference marked thereon,which form a part of this specification.

My invention relates to improvements in nut-locks, and particularly tothose having two nuts on the bolt; and its objects are to provide asimple and effective fastening for the nuts without the use of washers,keys, pins, or other devices supplemental to the main bolt and nuts, asheretofore used for the purpose, also to provide a nut-lock in the useof which both nuts can be put on the bolt simultaneously and notnecessarily singly, as in the devices wherein the bolt hasoppositelythreaded screws.

It is also the object of myinvention to permit the use of one or bothnuts of the common form, although the extent of utility of the boltmaybe increased by modification of the outer or looking nut, as will behereinafter described.

In the accompanying drawings, Figure 1 is Fig. 2 is a view of the same,showing the bolt in elevation and the nuts in section. Fig. 3 is a planview of one form of the locking-nut.

The bolt 4 has an inner screw-threaded portion 5, on which fits theinner or holding nut 6, and an outer screw-threaded portion 7 of reduceddiameter, on which fits the outer or looking nut 8, which may becountersunk or recessed centrally on its inner face, as shown in thedrawings.

- The operation of my invention depends mainly upon a difference inpitch of the threads upon the screw-threaded portions of the bolt, theinner portion 5 of larger diameter having a thread of greater pitch andthe outer portion 7 of smaller diameter having a thread of lesser pitch.Both threads are cut in the same direction, either right or left handed.The nuts are preferably made of the same diameter and then may be bothengaged and turned by a wrench until the inner one is advanced as far asdesired,when the wrench is shifted to the outer nut and the same screwedinto tight engagement with the inner nut.

It is evident that the inner nut upon a thread of greater pitch cannotturn backward or loosen while engaged by the outer nut, also that thetwo nuts cannot turn together to be unscrewed, also that the frictionalengagement between the opposing faces of the two nuts effectivelyprevents loosening or unscrewing of the outer nut by tending to causeboth nuts to turn together, which has the effect, owing to the greaterpitch of the threads of the inner nut, of locking the nuts more securelytogether.

When the portions of the bolt are oppositely threaded, as in manylock-nuts heretofore designed, the nuts normally tend to loosen andseparate unless prevented by pins, engaging teeth, and such devicesheretofore employed, while in myinvention when the nuts have beentightened together the loosening tendency has the effect of binding themtogether more securely. The tendency of the inner nut to move with theouter one, owing to the friction between them,increases with thewrenching force applied to the outer nut, because of the difierence intheir relative rate of longitudinal movement on the bolt. To unlock andremove the nuts, it is necessary to hold the inner not against movementwith one wrench and turn the outer nut with another.

To assist the frictional engagement between the nuts, one or both of theengaging faces may be roughened or ridged, as illustrated in Fig. 3, orslightly concaved, as shown greatly exaggerated in Fig. l, in whichlatter case the edges of the engaging faces of the nuts cut or bite intoeach other. Practically I find that the slight concavity of the innerface or the roughening and slight projection of the edges of the innerface caused by the shear of the die in the ordinary method of stampingor cutting nuts is sufficient to accomplish the effect indicated.

, The countersink or recess 9 permits of a greater range ofadjustability, in that the nut 8 can pass inwardly over the shoulderformed by the reduced portion of the bolt; but it will be seen that thecounter sink is not essential 1. In combination, a bolt having an inner'portion screw-threaded, an outer portion of reduced diameterscrew-threaded in the same direction with threads of lesser pitch", nutsfitting each portion and having slightly-concave faces adapted to enterinto locking engagement with each other by. means of the projectingcorners on each nut which, when the nuts are brought together, extendover and engage the edge of the other nut.

2. In combination, a bolt having an inner portion screw-threaded, anouter portion of reduced diameter screw-threaded in the same directionwith threads of lesser pitch, nuts fitting each portion and adapted toenter-into locking engagement with each other by means ofslightly-projecting corners on each nut which, when the nuts are broughttogether, extend over and engage the edge of the other nut.

3. In combination, a bolt having an inner portion screw-threaded, anouter" portion of reduced diameter sorew-threaded'inthe same directionwith threads of lesser pitch, nuts fitting each portion and engageablewith each other the engaging face of each nut having ridges andhavingslightly projecting corners which, when the nuts are brought together,extend over and engage the edge of the other nut.-

4. In combination, a bolt having an inner portion screw-threaded in onedirection, an outer portion of reduced diameter screwthreaded in thesame direction with threads of lesser pitch, a nut fitting the innerportion, and a nut fitting the outer portion having a central recess orcountersink enabling it to engage with the other nut over the shoulderformedby the reduced portion of the bolt, the engaging face of each nuthaving slightly-projecting corners which, when the nuts are broughttogether, extend over and engagethe edge of the other nut.

In testimony whereof I affix my signature in presence of two Witnesses.

THOMAS W. HINE.

